Percussion tools



June 9, 1959 P. L. E. GUILLEMIER 2,889,811

PERCUSSION TOOLS Filed Aug. 5, 1957 2 Sheets-Sheet 1 1NVE1yT0R. PierreLean Emile Gulllemler Bylaw, #1621410 H/S ATTORNEYS June 9, 1959 P. L.E. GUlLLEMlE'R PERCUSSION TOOLS 2 Sheets-Sheet 2 Filed Aug. 5, 1957 JNVENTOI. Pierre Leon E mile 6u///em/er H/S ATTORNE Y3 Unite PERCUSSIONTOOLS Pierre Leon Emile Guillemier, Paris, France, assignor to SocietedElectro-Chimie dElectro-Metallurgie et des Acieries Electriques dUgine,Paris, France, a corporation of France Application August 5, 1957,Serial No. 676,330 Claims priority, application France August 10, 1956 7Claims. c1. 121-32 The present invention relates to percussion orvibrating tools, such as mine drills, chisels, concrete breakers andriveting stamps or dies for pneumatic, electric or drop hammers.

The percussion tools of the present invention are of simpleconstruction, economical to fabricate and so constructed that breakagedue to metal fatigue of certain parts is reduced and thus repairs of thetools are less frequent.

It is known that percussion tools which fit on a pneumatic cylinder havea flange which is integrally forged with the tool. This flange preventsthe tool from being inserted too far into the socket of the hammercylinder and also maintains the tools in a limited path duringoperation. The flange on the tool contains internal stresses from theforging operation even though the tool is subsequently submitted tothermal treatments. These stresses ulimately result in prematurebreaking of the flange and necessitate frequent repairs and replacementsof the tool.

To prevent this disadvantage, I have replaced the onepiece forged flangeon the percussion tool with an attachable flange comprising a metallicouter ring or sleeve and an inner ring or sleeve of resilient materialconstructed and arranged to insure damping of the energy remaining inthe tool after each impulsion of the percussion tool. Thereby, asubstantial decrease in metal fatigue is obtained by the use of myattachable flange.

However, for the percussion tool to operate effectively, it is necessarythat a large part of the energy of the piston be transmitted to thetool. Thus it is extremely important that the flange position on thetool be maintained rigid and not slip due to the vibrations and impactsto which the tool is subjected. I have devised a unique system ofgrooves in the resilient part of my flange which maintain the flangerigid relative to the tool.

In the drawings, I have illustrated a present preferred embodiment of myinvention in which:

Figure 1 is a side view, partly in cross section, of a well-knownpercussion tool with a forged flange;

Figure 2 is a side view, partly in cross section, of a percussion toolaccording to the present invention;

Figure 3 is a cross section of the flange of the present invention takenon line III-III of Figure 2;

Figure 4 is an end cross section of the flange according to the presentinvention in unswaged condition;

Figure 5 is a cross section view of the flange taken on line VV ofFigure 4;

Figure 6 is an end cross section of a modified form of flange accordingto the present invention;

Figure 7 is a cross section of the modified flange taken on line VIIVIIof Figure 6;

Figure 8 is an end cross section of a second modified form of flangeaccording to the present invention; and

Figure 9 is a cross section of the second modified flange taken on lineIXIX of Figure 8.

Briefly, the present invention consists of a flange attachable to theshaft of a percussion tool. The flange consists of an outer metallicring or sleeve which surrounds an inner resilient ring or sleeve.Preferably, the inner resilient ring is comprised of several resilientelements distributed longitudinally along the percussion tool shaft.Each of the elements has internal or external grooves extendinglongitudinally of the element and parallel to the shaft of thepercussion tool. The resilient elements may also have internal orexternal grooves extending transversely of the shaft of the percussiontool. The purpose of the grooves and the spacing of the elements apartis to allow room for the resilient material to expand when placed undertension or compression; thereby the resilient material does not lose itselastic characteristics. If the resilient material was fabricated as onecontinuous sleeve, without any grooves, the material would quickly loseits elastic properties during operation of the tool and the flange wouldhave to be replaced. The grooves also result in the resilient membershaving a better grip on the shaft of the percussion tool.

The well-known percussion tool, as shown in Figure 1, consists of acylinder housing 10 containing a movable piston 11. This piston ismotivated in a well-known manner; for example, as shown in Model PB8A,Paving Breaker and Pile Driver manufactured by the Ingersoll- RandCompany. A shifter 12 is affixed within grooves 13 in the lower end ofthe cylinder housing 10 in any desirable manner; for example: by boltsor set screws (not shown). The shifter 12 consists of a bent platehaving an opening 14 there-through to permit the passage of a tool 15.The tool 15 consists of a fitting piece 16 on the upper end having anydesirable shape to prevent turning; for example: hexagon shaped. Thisfitting piece is slid into an opening 17 in the cylinder housing 10. Theopening 17 has the same shape as the fitting piece 16. Below the fittingpiece 16 is a forged flange 18 and below that a shaft 19 containing anintegral work head 20.

In operation, the piston 11 strikes the upper end of the fitting piece16, thereby propelling the tool 15 downwardly in Figure 1. The flange 18comes in contact with the top side 21 of the shifter 12, therebystopping the movement of the tool downwardly in Figure 1. The tool 15 isre turned to its upward position as shown in Figure 1 by the operator ofthe tool pressing down on the cylinder housing 10 by means of a handlein a well-known manner. Then the piston 11 again strikes the upper endof the fitting piece and the cycle is repeated.

The flange 18 has stresses therein due to the forging operation. Thesestresses cannot be entirely relieved by heat treatment and consequently,the flange 18 is very susceptible to breakage due to repeated impulsionagainst the shifter 12. The present invention is primarily directed toovercoming this disadvantage.

As shown in Figure 2, the present invention is constructed substantiallyin the same manner as the wellknown device shown in Figure 1 with theexception that the shaft 19 is continuous and contains no forged flange18. In place of the flange 18 is a metallic ring or sleeve 22 extendinga substantial distance along the shaft 19 and completely encompassingthe same. The metallic sleeve has a resilient ring or sleeve 23,preferably rubber, underneath it. The rubber sleeve completely encirclesthe shaft 19 and consists of three resilient elements 24 havinglongitudinally extending grooves 25 on their inner surfaces. Theresilient elements 24 are separated from each other by spaces 26 ofsufiicient width to enable the resilient material to expand when undertension or compression.

In fabricating the device of the present invention, the resilientelements 24 are placed on the shaft 19; the metallic ring 22 is placedover them as shown in Figures 4 and 5, and the metallic sleeve 22 isswaged in the manner shown in Figure 2 by bending the longitudinal endedges inwardly toward the axis of revolution of the sleeve and indentingthe metallic ring at least three places 27. The indentations 27 arecontinuous around the whole periphery of the sleeve. The resilientmaterial located radially inwardly toward the shaft 19 underindentations 27 is compressed, and thus the bond bet-ween the metallicring and the resilient material is increased and the bond between theresilient material and the shaft 19 is likewise increased.

Figure 6 illustrates a modification of the resilient sleeve of thepresent invention in that the elements 24 are joined together by a thinbridge of resilient material 28 located at the outer periphery of theresilient elements. Thus, the rubber sleeve is a continuous element butsubdivided by grooves 29 located at the one-third point of the sleeve.

The resilient sleeve shown in Figures 6 and 7 can be split along theline VIIVII to form two half cylinders which facilitates fabrication ofthe flange.

The metal sleeve shown in Figures 6 and 7 is swaged in the same manneras shown in Figure 2 after assembly on the shaft 19.

Figures 8 and 9 show a further modification of the resilient sleeve inthat the longitudinal grooves are located on the outer periphery of thesleeve and the grooves 29 are likewise located on the outer peripherywith resilient bridges 28 forming a continuous inner surface next toshaft 19.

The metal sleeve shown in Figures 8 and 9 is swaged in the same manneras shown in Figure 2 after assembly on the shaft 19.

The preferred material of construction for the sleeve 23 is rubber;however, it is within the scope of the present invention to fabricatethis sleeve from any material having sumcient resiliency to produce theresult desired.

It is further understood that the present invention may be applied toall shapes of percussion tool shafts, whether they be cylindrical,prismatic, etc.

While I have described a present preferred embodiment of my invention,it is to be understood that it may be otherwise embodied within thescope of the following claims.

I claim:

1. A percussion tool having an elongated'shaft having a work head on oneend thereof, means to reciprocate the shaft longitudinally, a resilientsleeve having grooves therein positioned around said shaft; said groovesinsuring adherence between the sleeve and the shaft such that the sleevedoes not slide along the shaft; said grooves further being of sufiicientsize to provide areas into which portions of the sleeve may move uponforce being applied to the sleeve; and a rigid metal sleeveconcentrically and rigidly mounted around the resilient sleeve.

2. A percussion tool as recited in claim 1 wherein some of said groovesextend transversely of the shaft and other of said grooves extendlongitudinally of the shaft.

3. A percussion tool as recited in claim 1 wherein said grooves extendtransversely of the shaft.

4. A percussion tool comprising an elongated shaft having a work head onone end thereof, means to reciprocate the shaft longitudinally, aplurality of resilient sleeves positioned around and spacedlongitudinally along said shaft; each of said sleeves having groovestherein to maintain the sleeves stationary on the shaft and provideareas into which portions of the sleeves may move upon forces beingapplied to the sleeves; and a rigid sleeve concentrically mounted aroundthe resilient sleeves.

5. A percussion tool described in claim 1 wherein said grooves in theresilient sleeves extend longitudinally.

6. In a percussion tool including a housing, means reciprocal within thehousing, a shifter plate affixed to the lower end of the housing, anelongated shaft passing through an opening in the shifter plate andhaving its upper end fitted into and movable longitudinally in the lowerend of the housing, a work head on the lower end of the shaft, saidreciprocal means being engageable with the upper end of the shaft tomove the shaft longitudinally, a plurality of resilient sleevespositioned around and spaced from each other along said shaft betweenthe housing and the shifter plate, said sleeves having internallongitudinally extending grooves; and a single metal sleeveconcentrically mounted around all the resilient sleeves, the metalsleeve being indented radially to insure adhesion between the metalsleeve and the resilient sleeves and between the resilient sleeves andthe shaft.

7. In a percussion tool including a housing, means reciprocal within thehousing, a shifter plate affixed to the lower end of the housing, anelongated shaft passing through an opening in the shifter plate andhaving its upper end fitting into and movable longitudinally inthe'lower end of the housing, a work head on the lower end of the shaft,said reciprocal means being engageable with the upper end of the shaftto move the shaft longitudinally, a continuous resilient sleevepositioned around said shaft between the housing and the shifter plate,said sleeve having internal separate transversely extending andlongitudinally extending grooves, and a metal sleeve concentricallymounted around the resilient sleeve, the metal sleeve being indentedradially to insure adhesion between the metal sleeve and the resilientsleeve, and the resilient sleeve and the shaft.

References Cited in the tile of this patent UNITED STATES PATENTS1,555,214 Johnson Sept. 29, 1925 1,856,646 Lee May 3, 1932 2,685,274Liddicoat Aug. 3, 1954 FOREIGN PATENTS 332,914 Great Britain July 14,1930 653,982 Great Britain May 30, 1951

